وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ يَزِيدَ بْنِ خُصَيْفَةَ، عَنْ عُرْوَةَ بْنِ الزُّبَيْرِ، أَنَّهُ قَالَ سَمِعْتُ عَائِشَةَ، زَوْجَ النَّبِيِّ صلى الله عليه وسلم تَقُولُ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ لاَ يُصِيبُ الْمُؤْمِنَ مِنْ مُصِيبَةٍ حَتَّى الشَّوْكَةُ إِلاَّ قُصَّ بِهَا أَوْ كُفِّرَ بِهَا مِنْ خَطَايَاهُ ‏"‏ ‏.‏ لاَ يَدْرِي يَزِيدُ أَيَّهُمَا قَالَ عُرْوَةُ ‏.‏

Yahya related to me from Malik from Yazid ibn Khusayfa that Urwaibn az-Zubayr said that he heard A'isha, the wife of the Prophet, mayAllah bless him and grant him peace, say, "The Messenger of Allah, mayAllah bless him and grant him peace, said, 'When a mumin is afflictedby something, even a thorn, it removes (or effaces) his wrongactions.' " Yazid did not know which of them Urwa said. Translation Not Available

Book reference: Muwatta Imam Malik Book 50 Hadith 1719
Web reference: Muwatta Imam Malik Book 50 Hadith 6